Hyperscore uses General MIDI technology to produce instrument sounds. General
MIDI provides up to 128 sounds, but ony allows 16 sounds to be active at any
one time. For this reason, the Hyperscore Instruments menu can only
have 16 instruments avalable at once.

However, you can choose which 16 Instruments out of the
total 128 you wish to use.

To change the instruments available in the Instruments Menu:

Choose ‘Change Instruments’ from the Instruments
Menu. In the pop up window which appears, the list on the left contains all
the possible instruments, arranged in groups, while the list on the right
contains the currently active set.

Choose which instrument you wish to replace from the list
on the right.

Choose the instrument you want to use instead from the list on the left.

Press the ‘Replace’ button.

The instrument list on the right will update to show
you the new active set. Click 'Apply' and then 'OK' to return to your
piece. The newly selected instrument will now appear in the
Instruments Menu.